I found that if you trade the bitcoin against some good altcoins such as the Monero, Dash or Ethereum, it could be quite profitable.
You are right he have to select those altcoins which have a good place and have a good volume of trade. with the above mentioned altcoinsa lot of traders are earning a good income so if he having that much experience will start trade with those altcoins then he will earn better.
Having big volumes makes some volatility of prices most of the time and this is where opportunities for traders comes in. When there are less movements of price of altcoins, then it will be difficult to trade and profit because you have to wait long in order to reach the price you would want to sell your current coins.
It is a matter of choosing the right asset, never trade in a less volume asset as that would not last, the game there is just a pump and dump and when you have put already a big investment thinking you can make profit, that is when the developer will just scam your investment. You need to be smart in choosing the right asset.